The device is codenamed 'Train' and it will be headed to AT&T as the Lumia 830. While we don't have a release date, yet, we do expect it to show up in the not-too-distant future.

The Lumia 830 is expected to be a mid-range successor to the Lumia 820, shown here

Images of a rumored Lumia 830 appear to be legitimate but it's hard to say if the phone in the picture is actually the Train handset. The information about heading to AT&T comes from a reliable source, so take it as fact until proven otherwise.

Seeing that the HTC One Windows Phone is headed to Verizon - and may well be an exclusive, as no other version have been spotted - AT&T will be in need of a premium Windows Phone before the holiday shopping. So far, the rumors have been quiet about what or if a new Lumia will arrive besides the 830. However, we do not expect the Lumia 830 to be a premium phone.

We will keep digging to see if we can find out more about the Lumia 830 but for those of you on AT&T, this is good news as it will give you another, more modern, Windows Phone to choose from when it is time to upgrade.